Genotoxic Effects in Mice Exposed to Radon Emissions in Indoor Conditions. Comparison between in utero and Neonatal Exposures

The purpose of this study was to develop a biological model to evaluate the genotoxic effects of natural emissions of Radon-222 and its decay products. To this aim, mice of the Swiss CD1 strain were exposed to Radon for different periods （adult life, early postnatal and in utero exposure） and two simple but accurate mutagenicity tests （Micronucleus test and the Comet assay） were applied to the peripheral blood of mice. The study was carried out in two small towns in Latium region--ltaly, where radon pollution is notoriously present due to the volcanic soils. One experiment was carried out in the cellar of a house in Ciampino （Rome） and two experiments were performed in an old cellar in Vetralla （Viterbo）. The results showed that in all mice groups exposed to natural emissions of radon and its decay products, the micronucleated erythrocytes frequency （ME） was significantly higher than that observed in the mice control. The single cell gel electrophoresis （Comet assay） was performed in lymphocytes of adult mice in the last experiment. The results for this test also show that DNA damage was higher than in the cells of the mice control and the cells of mice exposed for a shorter period of time. To confirm these findings, the single cell gel electrophoresis （Comet assay） was performed in lymphocytes of adult mice in the last experiment. Similarly, this result could be linked to a greater sensitivity of neonatal mice to radon emissions compared with intrauterine mice. Further investigations on the effects of radon and its decay products during the intrauterine life and the first neonatal period should be performed to better clarify its genotoxic activity.